Pressure responsive control valve for well tubing



P. S. SlZER PRESSURE RESPONSIVE CONTROL VALVE FOR WELL TUBING Jan. 1,1963 Filed Nov. 5. 1958 R m m W F w Fig.2

Fig.1

F. e p. l S p m DI ATTORNEY United States Patent 3,071,151 PRESflURERiESiPflNfllVE CONTRQTL VALVE FQR WELL TUBING Phillip S. Sizer, Dallas,TexL, assignor to Gris Engineering Qorporation, Tern, a corporation ofDelaware Filed Nov. 5, 1958, Ser. No. 772,330 14 Claims. (61. 137-496}This invention relates to well tools and more particularly to animproved pressure responsive flow control device for controlling theflow of fluids through a flow conductor, such as a well tubing.

One object of the invention is to provide a new and improved controldevice for use in a well flow conductor which is responsive to the fluidpressure within the conductor for controlling flow of fluidstherethrough, and having a valve structure which is protected againstcutting action of flowing fluids while the valve is open.

A further object of the invention is to provide a control device of thecharacter described which is designed to automatically shut off flow offluid through the well flow conductor in which it is installed when thepressure of the fluids flowing through the conductor drops below apredetermined value, and which is designed so that the valve can beopened atter it has closed to permit the resumption of flow of fluidsthrough the conductor.

Another object of the invention is to provide a well flow control deviceof the character described having a flow control member therein in theform or" a movable valve element which is biased toward a closedposition and which is moved to an open position by the pressure of thewell fluid in the flow conductor, and wherein the device is providedwith positive stops for limiting longitudinal movement of the movablevalve member.

An important object of the invention is to provide a flow control deviceadapted to be positioned or secured in a well flow conductor to shut oilflow of fluids through such well conductor when the pressure of thefluids in the conductor drops below a predetermined value, the valveelement being biased toward a closed position by a fluid pressure mediumacting on the movable element, and to provide such a control devicewherein the construction and arrangement of the valve elements is suchthat the valve will close even though the pressure fluid acting to biasthe valve member toward closed position should vary because of failureof the sealing elements of the pressure chamber.

Another object of the invention is to provide a flow control device ofthe character described wherein the flow through the valve isrectilinear in its direction so that the fluids flowing through thevalve do not tend to cut or wear away the valve elements rapidly.

A particular object of the invention is to provide a valve for use in acontrol device of the character set forth wherein both the valve closureelement and the valve seat against which the closure element acts areprotected against the cutting action of fluids flowing through the valveassembly during flow of such fluids, and are only exposed to the actionof the flowing fluids when the valve is being moved to the closedposition.

Another object of the invention is to provide a flow control device ofthe character described wherein the pressure at which the valve willclose may be adjusted by adjustment of the fluid pressure medium actingon the movable valve element.

Additional objects and advantages of the invention will be readilyapparent from the reading of the following description of a deviceconstructed in accordance with the invention and reference to theaccompanying rawings thereof, wherein:

FlGURE l is a view partly in elevation and partly 3,fl7l,l.5i Patenteddarn. l, 1963 in section of the upper portion of a control deviceconstructed in accordance with the invention;

FIGURE 2 is a view partly in elevation and partly in section of thelower portion of the control device of the FlGURE 1 showing the valveelement in open position;

FIGURE 3 is a view similar to FIGURE 2 showing the valve element inclosed position; and

FiGURE 4 is a fragmentary view, partly in elevation and partly insection showing the flapper valve of the control device in anintermediate position between its closed and open positions.

in the drawings, the numeral 2% designates a flow control device forcontrolling the flow of well fluids through a well conductor, such asthe usual well tubing (not shown). The control device 2% may beconnected at its upper end to the screw threaded lower end of a hangerand sealing tool Zill by means of which the control device may belowered into and anchored in the well tubing for the purpose ofcontrolling flow through such tubing. The hanger and sealing tool may beof any suitable design, such as, for example, the patent to Marshall andFredd, 2,698,056, wherein the anchoring and sealing member is positionedat and locked in sealing engagement in a special landing nipple in awell tubing string, or may be an anchoring and sealing device of thecharacter illustrated in the patent to H. C. Otis, 2,784,789, whereinthe locking mechanism is designed to be anchored at any position in awell flow conductor and the sealing element may be moved into sealingengagement with such well flow conductor to direct flow through thevalve element attached to the anchoring and sealing mechanism.

The control device 2% includes an outer tubular member 263 whichcomprises an upper sub 214, a sleeve 215 threaded on the lower reducedend of the upper sub 21 and a tubular plug 216 threaded in the lower endof the sleeve 215. A spring biased inwardly closing equalizing valve 2%having a nose portion 292a projecting into the bore of the upper sub 214may be incorporated in the upper sub for the purpose of opening thevalve as will be hereinafter more fully described.

The outer sleeve 215 is provided with an internal flange 217intermediate its ends having an internal annular recess 21% in which anannular seal member 219 and cooperating Ci-ring 226 may be disposed. Theseal member engages the external surface of an elongate tubular valveelement or sleeve 225 which is slidable longitudinally within the outersleeve to seal between said outer sleeve and said valve sleeve 225. Thevalve element or sleeve 225 is telescoped in the outer sleeve 21S and isprovided at its upper end with an external annular piston flange 23%),disposed above the flange 217 and having an external annular recess 231itherein. Au annular seal member 232 and a cooperating O-ring 233 aredisposed in the recess 231 and the seal member is biased outwardly intosealing engagement with the internal wall surface of the outer sleeve215 to seal between the valve element flange and said outer sleeve.

The seal members 21d and 232 provide a fluid tight eal between the valveelement 225 and the outer sleeve 215 whereby a gas tight chamber 235 isprovided between the valve element 225 and the sleeve 215 and betweenthe flanges 217 and 239. A charge of gas may be introduced or injectedinto the chamber 235 through the ports 237 and 238 of the outer sleeve.The port 237 communicates with the interior of the outer sleeve abovethe seal member 219 so that any gas introduced into the lateral port 237may flow upwardly between the internal surface 244! provided by theflange 217 and the external wall surface of the valve element into thechamber 235.

The port 237 may be closed by means of a plug 242, threaded in anenlarged bore 243 of the sleeve 215, which compresses a gasket 244against the annular shoulder m3 245 adjacent the lateral port 237. Theangularly extending port 238 of course may communicate with the port 217only when the plug 242 is screwed outwardly. Gas may be injected intothe port 233 by means of a suitable fitting, not shown.

A spring 25% may be disposed in the chamber 235 with its opposite endsbearing against the downwardly facing shoulder 251 of the externalflange 230 of the valve element 225 and against the upper annularshoulder 252 of the sleeve 215. It will be apparent that the spring 256and the charge of gas in the chamber 235 bias the valve element to anupper closed position.

The valve element 225 is provided at its lower end with an annular valveseat 255 which, when the valve is in its lower open position, abuts theupwardly and inwardly inclined annular protective surface 256 of theplug 216 which protects the valve seat against undue wear by fluidsflowing through the outer tubular member by way of the bore 260 of theouter tubular member 283 and the bore 261 of the valve element 225.

It will be apparent that since the upper ends of the sleeve and of theexternal flange 230 are exposed to the pressure of the well fluidsflowing through the bores 26 and 261, when the control device 210 ispositioned in a well flow conductor, or well tubing (not shown), fluidpressure present in the tubing will pass upwardly around the sealingelement of the hanger and sealing tool and enter the bore of such tool,from whence it will also enter the upper end of the outer sleeve 215 andact downwardly on the flange piston 23%. If the fluid pressure soentering the upper end of the outer sleeve is sufficiently high, thevalve member Will be moved downwardly to open position. After thecontrol device has been anchored or secured in locked sealing positionin the tubing, the valve member 225 will be held in the lower openposition illustrated in FIGURE 1 against the combined forces of thespring 258 and of the charge of the gas so long as the fluid pressureexceeds the predetermined value for which the spring and gas charge inthe chamber 235 are set.

When the valve element 225 is moved upwardly by the combined forces ofthe spring and of the charge in the chamber 235 due to the fall of thepressure of the well fluids in the tubing above the control device belowthe predetermined value, a flapper valve 27% having a beveled sealsurface 271 on a valve body 272 is pivoted upwardly into engagement withthe lower end of the valve element to close the bore 261 of the valveelement by the engagement of the annular beveled surface 271 of theflapper valve with the valve seat 255 at the lower end of the valveelement. The flapper valve is disposed in a lateral longitudinal slot273 formed in the wall of the sleeve 215, and is retained therein by ashaft 275 which extends outwardly from the upwardly extending integralarm 276 of the body 272 of the flapper valve 279 into aligned verticalslots 277 in the sleeve which extend outwardly from the slot 273. Theshaft 275 extends through a suitable transverse bore in the arm 276 andis rigidly secured therein by means of a set screw 28% threaded in thearm.

The arm 276 is also provided with a bell crank or lever lug 282 whichextends at a right angle with respect to the arm. The outer end of thelug extends into an external annular recess 283 on the lower end of thevalve element 225. The external annular recess 283 provides an annularupwardly facing trip shoulder 235 which is adapted to engage thedownwardly facing shoulder 286 formed by the underside of the lever lug282 to pivot the flapper valve 270 in an upwardly swingingmanner whenthe valve element 225 is moved upwardly. Such movement of the flappervalve 279 causes the flapper valve body 272 to move into the upwardflowing stream of fluids and thus into engagement with the lower end ofthe valve element 225, which is now disposed above the valve body 272,the beveled shoulder 271 engaging the valve seat 255.

The upward movement of the valve element 225 is stopped or limited byengagement of the upper end of said valve element with the lower end ofthe upper sub 214, and the shaft 275 is movable vertically in the slots277 to permit proper adjustment of the valve body relative to the valveseat 255 into seated sealing position. It is apparent that the upwardlyflowing stream of well fluids urges the valve body upwardly intoengagement with the lower end of the valve element 225 whereby, when thevalve element 225 is moved upwardly due to the decrease in the pressureof the well fluids flowing through the valve element, the flapper valvewill be pivoted into the stream of fluids and then moved by such streaminto engagement with the lower end of the valve element. The pressure ofthe well fluid will hold the flapper valve in the closed positionillustrated in FIGURE 3, preventing flow of well fluids through the flowcontrol device 214).

It will be particularly noted that should the seals holding the fluidpressure charge in the chamber 235 leak or for any reason, the higherwell pressure will enter the chamber 235, substantially equalizingpressures on both sides of the piston flange 230, so that the spring 256will move the movable valve element 225 upwardly toward closed position,thus causing the valve to close prematurely. The valve will close atsubstantially the time at which the higher pressure of the well fluidsentering the chamber 235 plus the force of the spring equals or slightlyexceeds the downward force of the pressure of the well fluids actingdownwardly on the upper end of the piston flange 236 at the upper end ofthe valve sleeve or element 225, rather than at the lower pressurepredetermined by the charge in the chamber 235. This operation of thevalve provides an additional desirable factor of safety, since the valvewill thus positively close prematurely and warn the operator of thefailure of the seals 219 or 232, as the case may be. Thus, the controldevice may be removed, the seals replaced and the chamber recharged, toagain effect closure of the control device at the desired predeterminedpressure condition in the well. But in any event, the valve of thecontrol device will always close to prevent an undesired escape of wellfluids from the well tubing, should the surface controls or flow linesbe damaged in such a manner as to permit an escape of fluids fro-m thetubing resulting in a reduction in the pressure of the fluids in thetubing above the Well device to the predetermined value for which thecontrol device is set.

The valve element 225 and flapper valve 270 will move back to their openpositions, illustrated in FIGURE 2, only when the pressure above andbelow the flapper valve is equalized and such equalization of pressuremay be accomplished by the opening of the valve 201 in the upper sub 214to admit fluid pressure from below the control device into the bore ofthe sleeve 215, whereupon, after suflicient fluid pressure has beenadmitted, the flapper valve will move downwardly and outwardly, due toits own weight, out of engagement with the valve seat 255.Simultaneously, the pressure exerted on the upper end of the valveelement 225 and the piston flange 230, if the pressure of the valvefluids is above the predetermined value, will cause the valve element toagain move downwardly to the open position illustrated in FIGURE 2against the resistance of the spring 250 and the charge of gas in thechamber 235.

It will thus be seen that the control device 200 includes an outertubular member 2G3, an inner tubular valve element 225 slidably mountedin the outer tubular member for limited longitudinal movement therein,since upward movement of the valve element is limited by the engagementof the upper end of the valve element with the lower end of the uppersub 214 and downward move-- ment thereof in the outer tubular member 233is limited by the engagement of the seat 255 at the lower end of saidvalve element with the inclined annular surface 256 at the upper end ofthe tubular plug 216 when the valve; element is in its lower position.

It will further be seen that the tubular member is provided with a valvemeans which is movable into engagement with the lower end of the valveelement to close the longitudinal bore 261 thereof upon upward movementof the valve element in the outer tubular memher 2%.

It will also be apparent that a valve 270 is pivotally mounted on theouter tubular member 263, and that the valve and the valve element 225are provided with coacting means which pivot the valve 278 into theflowing stream of well fluids which then move the valve into engagementwith the valve seat 255 upon upward movement of the valve element in theouter tubular member 2%.

It will likewise be seen that the sealing surfaces of the valve seat 255and of the valve body 270 are, when not coengaged, protected againstwear since the valve element seat 255 abuts the upwardly inclinedprotective surface 256 of the plug 216 and is thu disposed out of thestream of flow of well fluids, while the surface 271 of the valve body27%? is, when in open inoperative position, disposed in the outer sleeve215 outwardly of the valve element 225, also out of the stream of flowof the valve fluids.

It is also readily apparent that a new and improved flow control devicehas been illustrated and described which is provided with alongitudinally movable valve element and a cooperating flapper valve,which when in their upper closed position, prevent flow of well fluidsthrough the outer tubular member, and which when in their lower openposition, permit such flow of well fluids through the tubular valvemember, and thus through the well tubing past the anchoring and sealingmeans.

it will further be apparent that the valve elements of the flow controldevice are so disposed that the flow of fluids through the tubular valveelement is rectilinear, without turns or changes in direction of flow,and that the seating and sealing elements of the tubular valve elementand of the flapper valve element are protected against the cuttingaction of the well fluids flowing through the control device, since theinclined protective surface at the upper end of the tubular plug 216directs flow past the seat at the lower end of the valve element, andall flow when the valve is open is directed past the flapper valve.

it is also apparent that the flow control device is provided with meansfor opening the same after it has been closed, that such opening may beaccomplished by means of the insertion of a suitable tool into the welltubing from the surface to engage the equalizing valve 291 to admitfluids into the well tubing above the valve elements in suflicientamount to open the valve. Likewise, fluid may be introduced from anextraneous source into the tubing at the surface to raise the pressurein the tubing to a value in excess of the predetermined pressure atwhich the valve will open.

The foregoing description of the invention is explanatory only, andchanges in the details of the constructions illustrated may he made bythose skilled in the art, within the scope of the appended claims,without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

l. A Well flow control device including: a tubular outer member; atubular valve element longitudinally movably mounted in said tubularouter member and having a valve seat at its lower end; a valve closuremeans connected to said tubular member also movably mounted in saidtubular member and engageable with the valve seat at the lower end ofsaid tubular valve element to close the same; means in said tubularouter member biasing said tubular valve element longitudinally thereinto a position wherein said seat is closingly engaged by said valveclosure means to prevent flow of fluids through said outer tubularmember comprising a fixed predetermined charge of gaseous pressureconfined within said outer member and acting upon said tubular valveelement to move said valve element toward such closed position upon theoccurrence of a predetermined pressure condition within the bore of saidtubular member above said valve element, such gaseous pressure chargecontrolling the pressure conditions under which the valve element willbe moved to ward closed position; and means on said valve elementresponsive to fluid pressure of the fluids flowing through said tubularouter member and within the tubular member downstream of the valveelement for moving the valve element longitudinally in said tubularmember to a position out engagement with said valve closure means topermit flow of fluids through said tubular valve member, whereby thepressure of the fluids flowing through said valve member acts thereon tohold the same in open position.

2. A well flow control device including: a tubular outer member; anelongate tubular valve element longitudinally movably mounted in saidouter tubular member and hav ing a valve seat at its lower end; a valveclosure member connected to said outer tubular member swingably mountedin said outer tubular member and engageable with the valve seat at thelower end of said tubular valve element to close oit flow through saidouter tubular memer; means in said outer tubular member biasing saidvalve element longitudinally of said tubular member comprising a fixedpredetermined charge of gaseous fluid confined within said tubularmember and acting on said valve element for moving the same to aposition in Which said closure member engages the valve member to closeoff flow through the outer tubular member; and means on said valveelement responsive to fluid pressure of the fluids flowing through saidtubular outer member and within the tubular member downstream of thevalve element for moving the valve ele- .ent longitudinally against theresistance of said biasing means to move the closure member out ofclosing engag ment with the seat at the lower end or" said valve elementto permit flow of fluids upwardly through the valve element, suchdownward movement of the valve element moving the closure member to aposition in which the closure member cannot engage the valve element toclose off flow through the outer tubular member.

3. A well flow control device including: a. tubular outer member; anelongate tubular valve element longitudinally movably mounted in saidouter tubular member and having a valve seat at its lower end; means insaid tubular member comprising a predetermined fixed gaseous pressurecharge confined within said tubular member and acting on said valveelement biasing said valve element longitudinally therein to a firstposition in said tubular member; a valve closure member connected tosaid tubular outer member movably mounted in said tubular outer memberand engageable with the valve seat at the lower end of the valve elementto close oif flow through the tubular member when said valve element isin said first position; and means on said valve element responsive tofluid pressure of the fluids flowing through said tubular outer memberand within the tubular member downstream of the valve element for movingthe valve element longitudinally in said tubular member against theresistance of said biasing means to a second position when the fluidpressure in the tubular member exceeds a predetermined value controlledby said charge of gaseous fluid; said valve closure means being held outof flow preventing engagement with the valve seat at the lower end ofsaid valve element when said valve element is in said second position,whereby flow of fluids may take place through the outer tubular member.

4. A well flow control device including: .an outer tubular member; anelongate tubular valve element longitudinally movably mounted in saidouter tubular member and having a valve seat at its lower end; means insaid outer tubular member biasing said valve element longitudinallytherein to a first position in said tubular member and comprising afined predetermined charge of gaseous fluid confined Within said tubularmember and acting on said valve element; a valve closure clementconnected to said outer tubular member swingably mounted in said outertubular member and positioned to engage the valve seat at the lower endof said valve element when said valve element is in said first positionto close the tubular bore of said valve element; and means on said valveelement responsive to fluid pressure of the fluids flowing through saidtubular outer member and within the tubular member downstream of thevalve element for moving the valve element against the resistance ofsaid biasing means when the fluid pressure of the fluids flowing throughthe valve and in the tubular member downstream of the valve closureelement exceeds a predetermined value controlled by said charge ofgaseous fluid to a second position in said tubular member; said valveelement when so moved swingably moving said valve closure member to aposition out of bore closing engagement with the end thereof to open thetubular bore of the valve element to flow therethrough.

5. A well tool for a well flow conductor including: an elongate outermember having a longitudinal bore therein; hanger and sealing means onsaid outer member for holding the outer member in a selected desiredposition in a well flow conductor and for sealing between the outermember and the Well flow conductor whereby flow of fluids in the Wellconductor may occur only through such bore of the outer member; a valveelement having a longitudinal flow passage mounted in said bore of theouter member for limited longitudinal movement between an upper closedposition and a lower open position, said valve element and said outermember having engageable means, for closing said flow passage of saidvalve element when said valve element is in its upper closed position toprevent flow of fluids through the well tool, said engageable meanscomprising a valve seat provided on the lower .end of said valve elementand a valve pivotally mounted on said outer member and movable pivotallyand longitudinally into bore closing engagement with said valve seat toclose said flow passage upon upward movement of said valve element toits upper position; and means on said valve element providing opposedsurfaces exposed to the pressure of fluids flowing through said valveelement and wherein the area exposed to such pressure downstream of thevalve element is larger than the area exposed to pressure upstreamthereof, so that the pressure of the fluids acting on said areas of saidvalve element provides means responsive to such fluid pressure formoving the valve element longitudinally in the tubular outer member tothe lower position in said tubular outer member.

6. A well tool for a well flow conductor including: an elongate outermember having a longitudinal bore therein; hanger and sealing means onsaid outer member for holding the outer member in a selected desiredposition in a well flow conductor and for sealing between the outermember and the well flow conductor whereby flow of fluids in the wellconductor may occur only through such bore of the outer member; a valveelement having a longitudinal flow passage mounted in said bore of theouter member for limited longitudinal movement between an upper closedposition and a lower open position; means in said outer member biasingsaid valve element toward the upper closed position in said outermember; said valve element and said outer member having engageable meansfor closing said flow passage of said valve element when said valveelement is in its upper closed position to prevent flow of fluidsthrough the well tool, said engageable means comprising a valve seatprovided on the lower end of said valve element and a valve pivotallymounted on said outer member and movable into engagement with said valveseat to close said flow passage upon upward movement of said valveelement to its upper position said outer member having a protectivesurface for engaging said valve seat when the valve element is in itslower open position to protect said valve seat against wear by the flowof well fluids therepast; and means on said valve element providingopposed surfaces exposed to the pressure of fluids flowing through saidvalve element and wherein the area exposed to such pressure downstreamof the valve element is larger than the area exposed to pressureupstream thereof, so that the pressure of the fluids acting on saidareas of said valve element provides means responsive to such fluidpressures for moving the valve element longitudinally in the tubularouter member to the lower position in said tubular outer member.

7. A well tool for a Well flow conductor including: an elongate outermember having a longitudinal bore therein; hanger and sealing means onsaid outer member for holding the outer member in a selected desiredposition in a Well flow conductor and for sealing between the outermember and the well flow conductor whereby flow of fluids in the wellconductor may occur only through such bore of the outer member; a valveelement having a longitudinal flow passage mounted in said bore of theouter member for limited longitudinal movement between an upper closedposition and a lower open position; means in said outer member biasingsaid valve element toward the upper closed position in said outermember; said valve element and said outer member having engageable meansfor closing said flow passage of said valve element when said valveelement is in its upper closed position to prevent flow of fluidsthrough the well tool, said engageable means comprising a valve seatprovided on the lower end of said valve element and a valve pivotallyand longitudinally movably mounted on said outer member and movable intobore closing engagement with said valve seat to close said flow passageupon upward movement of said valve element to its upper position, saidvalve member being disposed outwardly of said valve member out of thestream of flow of well fluids through the flow conductor when the valveelement is in its lower open position whereby said valve member is keptout of the stream of flow of well fluids when the valve element is inits lower open position; and means on said valve element providingopposed surfaces exposed to the pressure of fluids flowing through saidvalve element and wherein the area exposed to such pressure downstreamof the valve element is larger than the area exposed to pressureupstream thereof, so that the pressure of the fluids acting on saidareas of said valve element provides means responsive to such fluidpressures for moving the valve element longitudinally in the tubularouter member to the lower position in said tubular outer member.

8. A well tool for a Well flow conductor including: an elongate outermember having a longitudinal bore therein; hanger and sealing means onsaid outer member for holding the outer member in a selected desiredposition in a well flow conductor and for sealing between the outermember and the well flow conductor whereby flow of fluids in the wellconductor may occur only through such bore of the outer member; a valveelement having a longitudinal flow passage mounted in said bore of theouter member for limited longitudinal movement between an upper closedposition and a lower open position; means in said outer member biasingsaid valve element toward the upper closed position in said outermember; said valve element and said outer member having engageable meansfor closing said flow passage of said valve element when said valveelement is in its upper closed position to prevent flow of fluidsthrough the Well tool, said engageable means comprising a valve seatprovided on the lower end of said valve element and a valve pivotallymounted on said outer member and movable into engagement with said valveseat to close said flow passage upon upward movement of said valveelement to its upper position; and means on said valve element providingopposed surfaces exposed to the pressure of fluids flowing through saidvalve element and wherein the area exposed to such pressure downstreamof the valve element is larger than the area exposed to pressureupstream thereof, so that the pressure of the fluids acting on saidareas of said valve element provides means responsive to such fluidpressures for moving the valve element longitudinally in the tubularouter member to the lower position in said tubular outer member; saidouter member having a protective surface for engaging said valve seatwhen the valve element is in its lower open position to protect saidvalve seat against wear by the flow of well fluids therepast, said valvemember being disposed outwardly of said valve member out of the streamof flow of well fluids through the flow conductor when the valve elementis in its lower open position whereby said valve member is kept out ofthe stream of flow of well fluids when the valve element is in its loweropen position.

9. A well tool for a well flow conductor including: an elongate outermember having a longitudinal bore therein; hanger and sealing means onsaid outer member for holding the outer member in a desired selectedposition in a well flow conductor and for sealing between the outermember and the well flow conductor whereby flow of fluids in the Wellconductor may occur only through such bore of the outer member; a valveelement having a longitudinal flow passage mounted in said bore of theouter member for limited longitudinal movement between an upper closedposition and a lower open position; means in said outer member biasingsaid valve element toward the upper closed position in said outermember; said valve element and said outer member having engageable meansfor closing said flow passage of said valve element when said valveelement is in its upper closed position to prevent flcw of fluidsthrough the well tool, said engageable means comprising a valve seatprovided on the lower end of said valve element and a valve pivotallymounted on said outer member and movable into engagement with said valveseat to close said flow passage upon upward movement of said valveelement to its upper position, said valve member being pivotally mountedon said outer member and having an inwardly projecting arm when it is inan open position, said valve element having a trip means engageable withsaid arm upon upward movement of said valve element through apredetermined distance from its open position to its closed position topivot said valve member inwardly and upwardly toward said valve seat toclose said valve passage upon upward movement of said valve element insaid outer member; and means on said valve element providing opposedsurfaces exposed to the pressure of fluids flowing through said valveelement and wherein the area exposed to such pressure downstream of thevalve element is larger than the area exposed to pressure upstreamthereof, so that the pressure of the fluids acting on said areas of saidvalve element provides means responsive to such fluid pressures formoving the valve element longitudinally in the tubular outer member tothe lower position in said tubular outer member.

10. A well tool for a well flow conductor including: an elongate outermember having a longitudinal bore therein; means on said outer memberfor securing said outer member in a selected position in a well flowconductor and for directing flow of fluids in the well flow conductorthrough the bore of said outer member; a tubular valve element having alongitudinal flow passage therethrough and a valve seat at its lowerend, said valve element being mounted in the bore of said outer memberfor limited longitudinal movement therein between an upper position anda lower position; a valve closure member swingably and longitudinallymovably mounted on said outer member and movable into bore closingengagement with the seat at the lower end of said valve element forclosing said flow passage of said valve element when said valve elementis in its upper position to prevent flow of fluids through the welltool; means on said valve element providing an area exposed to thepressure of fluids flowing through the valve element and present withinthe outer member whereby such fluids move said valve element downwardlywithin the bore of the outer member to the lower position therein; saidvalve element when moved downwardly to its lower position engaging saidclosure member to swingably move the same out of bore closing engagementwith the lower end of said valve element; said valve element and saidouter member having means thereon defining a fluid tight chambertherebetween for receiving a fixed predetermined charge of compressiblegas for biasing said valve element upwardly toward its closed position,whereby a predetermined fluid pressure must be present in the outermember and acting on the valve element to move the valve elementdownwardly in said outer member against the biasing force of thecompressible gas in said chamber.

11. A well tool for a well flow conductor including: an elongate outermember having a longitudinal bore therein; means on said outer memberfor securing said outer member in a desired selected position in a wellflow conductor and for directing flow of fluids in the well flowconductor through the bore of said outer member; a tubular valve elementhaving a longitudinal flow passage therethrough and a valve seat at itslower end, said valve element being slidably mounted in the bore of saidouter member for limited longitudinal movement therein between an upperposition and a lower position; a valve closure member swingably andlongitudinally movably mounted on said outer member and swingable intobore closing engagement with the seat at the lower end of said valveelement for closing said flow passage of said valve element when saidvalve element is in its upper position to prevent flow of fluids throughthe well tool; said valve element when moved downwardly to its lowerposition engaging said closure member to swingably move the same out ofbore closing engagement with the lower end of said valve element; saidvalve element and said outer member having means thereon defining afluid tight chamber therebetween for receiving a fixed predeterminedcharge of compressible gas for biasing said valve element upwardlytoward its closed position; and means on said valve element responsiveto fluid pressure of the fluids flowing through said tubular outermember and within the outer member above said valve element for movingsaid valve element downwardly to said lower position against theresistance of said biasing charge in said chamber, when the fluidpressure within the outer member above the valve member exceeds apredetermined value controlled by said predetermined fixed charge ofcompressible gas, said charge of gas also determining the pressureconditions within the bore of the outer member above the valve elementunder which the valve element will be moved upwardly toward closedposition.

12. A well tool for a well flow conductor including: an elongate outermember having a longitudinal bore therein; means on said outer memberfor securing said outer member in a desired selected position in a wellflow conductor and for directing flow of fluids in the well flowconductor through the bore of said outer member; a tubular valve elementhaving a longitudinal flow passage therethrough mounted in the bore ofsaid outer member for limited longitudinal movement therein between anupper position and a lower position; said valve element having a seat atthe lower end of its bore; a valve closure member swingably mounted onsaid outer member and swingable into engagement with the seat at thelower end of said valve element for closing said flow passage of saidvalve element when said valve element is in its upper position toprevent flow of fluids through the well tool; said valve element whenmoved downwardly to its lower position engaging said closure member toswingably move the same out of engagement with the lower end of saidvalve element; said valve element and said outer member having meansthereon defining a fluid tight chamber therebetween for receiving acharge of compressible gas for biasing said valve element upwardlytoward its closed position; means on said valve element exposed ill tothe pressure of fluids flowing through said valve element and in theouter member to move said valve element downwardly toward its openposition in said outer element when the pressure of the fluids presentin said outer member and acting on said valve element exceeds apredetermined value; and means on said outer member engageable with thelower end of said movable valve element when said valve element is inits lower position to protect the seat at the lower end of said valveelement against the cutting action of the fluids flowing through saidvalve element.

13. A well tool for a well flow conductor including: an elongate outermember having a longitudinal bore therein; means on said outer memberfor securing said outer member in a selected position in a well flowconductor and for directing flow of fluids in the well flow conductorthrough the bore of said outer member; a tubular valve element having alongitudinal flow passage therethrough mounted in the bore of said outermember for limited longitudinal movement therein between an upperposition and a lower position; said valve element having a valve seat atthe lower end of the flow passage therethrough; a valve closure memberswingably mounted on said outer member and swingable into engagementwith the seat at the lower end of said valve element for closing saidflow passage of said valve element when said valve element is in itsupper position to prevent flow of fluids through the well tool; saidvalve element when moved downwardly to its lower position engaging saidclosure member to swingably move the same out of engagement with thelower end of said valve element; said valve element and said outermember having means thereon defining a fluid tight chamber therebetweenfor receiving a charge of compressible gas for biasing said valveelement upwardly toward its closed position; means on said valve elementresponsive to fluid pressure of the fluids flowing through said tubularouter member and within the outer member above said valve element formoving said valve element downwardly to said lower position against theresistance of said biasing charge in said chamber, when the fluidpressure within the outer member above the valve member exceeds apredetermined 12 value; and means on said outer member engageable withthe lower end of said movable valve element when said valve element isin its lower position to protect the seat at the lower end of said valveelement against the cutting action of the fluids flowing through saidvalve element.

14. A well flow control device including: an outer tubular member; anelongate tubular valve element longitudinally movably mounted in saidouter tubular memher; said valve element having a seat formed at one endthereof; means in said tubular member biasing said valve elementlongitudinally therein to a first position in said tubular member; avalve closure element swingably mounted in said outer tubular member andpositioned to engage said seat at said one end of said valve elementwhen said valve element is in said first position to close the tubularbore of said valve element; and means on said valve element responsiveto fluid pressure of the fluids flowing through said tubular outermember and within the tubular member downstream of the valve element formoving the valve element against the resistance of said biasing meanswhen the fluid pressure exceeds a predetermined value to a secondposition in said tubular member; said valve element when so movedswingably moving said valve closure member to a position out ofengagement with the end thereof to open the tubular bore of the valveelement to flow therethrough; and means on said outer member engageablewith said one end of said movable valve element when said valve elementis in its second position to protect the seat at said one end of saidvalve element against the cutting action of the fluids flowing throughsaid valve element.

References Qited in the file of this patent UNITED STATES PATENTS Conradet al Sept. 13, 1960

1. A WELL FLOW CONTROL DEVICE INCLUDING: A TUBULAR OUTER MEMBER; ATUBULAR VALVE ELEMENT LONGITUDINALLY MOVABLY MOUNTED IN SAID TUBULAROUTER MEMBER AND HAVING A VALVE SEAT AT ITS LOWER END; A VALVE CLOSUREMEANS CONNECTED TO SAID TUBULAR MEMBER ALSO MOVABLY MOUNTED IN SAIDTUBULAR MEMBER AND ENGAGEABLE WITH THE VALVE SEAT AT THE LOWER END OFSAID TUBULAR VALVE ELEMENT TO CLOSE THE SAME; MEANS IN SAID TUBULAROUTER MEMBER BIASING SAID TUBULAR VALVE ELEMENT LONGITUDINALLY THEREINTO A POSITION WHEREIN SAID SEAT IS CLOSINGLY ENGAGED BY SAID VALVECLOSURE MEANS TO PREVENT FLOW OF FLUIDS THROUGH SAID OUTER TUBULARMEMBER COMPRISING A FIXED PREDETERMINED CHARGE OF GASEOUS PRESSURECONFINED WITHIN SAID OUTER MEMBER AND ACTING UPON SAID TUBULAR VALVEELEMENT TO MOVE SAID VALVE ELEMENT TOWARD SUCH CLOSED POSITION UPON THEOCCURRENCE OF A PREDETERMINED PRESSURE CONDITION WITHIN THE BORE OF SAIDTUBULAR MEMBER ABOVE SAID VALVE ELEMENT, SUCH GASEOUS PRESSURE CHARGECONTROLLING THE PRESSURE CONDITIONS UNDER WHICH THE VALVE ELEMENT WILLBE MOVED TOWARD CLOSED POSITION; AND MEANS ON SAID VALVE ELEMENTRESPONSIVE TO FLUID PRESSURE OF THE FLUIDS FLOWING THROUGH SAID TUBULAROUTER MEMBER AND WITHIN THE TUBULAR MEMBER DOWNSTREAM OF THE VALVEELEMENT FOR MOVING THE VALVE ELEMENT LONGITUDINALLY IN SAID TUBULARMEMBER TO A POSITION OUT OF ENGAGEMENT WITH SAID VALVE CLOSURE MEANS TOPERMIT FLOW OF FLUIDS THROUGH SAID TUBULAR VALVE MEMBER, WHEREBY THEPRESSURE OF THE FLUIDS FLOWING THROUGH SAID VALVE MEMBER ACTS THEREON TOHOLD THE SAME IN OPEN POSITION.